--- a/src/pyams_content/component/paragraph/milestone.py	Thu Apr 05 15:30:06 2018 +0200
+++ b/src/pyams_content/component/paragraph/milestone.py	Thu Apr 05 16:19:59 2018 +0200
@@ -9,47 +9,45 @@
 # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
 # FOR A PARTICULAR PURPOSE.
 #
-from pyramid.events import subscriber
 
 __docformat__ = 'restructuredtext'
 
 
 # import standard library
 from persistent import Persistent
+from pyramid.events import subscriber
+from zope.annotation import IAnnotations
+from zope.container.contained import Contained
+from zope.container.ordered import OrderedContainer
+from zope.interface import implementer
+from zope.lifecycleevent import ObjectCreatedEvent, IObjectAddedEvent, ObjectModifiedEvent, IObjectModifiedEvent, \
+    IObjectRemovedEvent
+from zope.location import locate
+from zope.location.interfaces import ISublocations
+from zope.schema.fieldproperty import FieldProperty
+from zope.schema.vocabulary import SimpleVocabulary, SimpleTerm
+from zope.traversing.interfaces import ITraversable
 
+# import packages
+from pyams_catalog.utils import index_object
+from pyams_content import _
+from pyams_content.component.paragraph import BaseParagraph, BaseParagraphFactory, BaseParagraphContentChecker
 # import interfaces
 from pyams_content.component.paragraph.interfaces import IParagraphContainerTarget, IParagraphContainer, \
     IParagraphFactory
 from pyams_content.component.paragraph.interfaces.milestone import IMilestone, IMilestoneContainer, \
     IMilestoneContainerTarget, MILESTONE_CONTAINER_KEY, IMilestoneParagraph, MILESTONE_PARAGRAPH_TYPE, \
     MILESTONE_PARAGRAPH_RENDERERS
+from pyams_content.features.checker import BaseContentChecker
 from pyams_content.features.checker.interfaces import IContentChecker, MISSING_VALUE, MISSING_LANG_VALUE, ERROR_VALUE
+from pyams_content.features.renderer import RenderedContentMixin, IContentRenderer
 from pyams_form.interfaces.form import IFormContextPermissionChecker
 from pyams_i18n.interfaces import II18n, II18nManager, INegotiator
-from zope.annotation import IAnnotations
-from zope.location.interfaces import ISublocations
-from zope.traversing.interfaces import ITraversable
-
-# import packages
-from pyams_catalog.utils import index_object
-from pyams_content.component.paragraph import BaseParagraph, BaseParagraphFactory, BaseParagraphContentChecker
-from pyams_content.features.checker import BaseContentChecker
-from pyams_content.features.renderer import RenderedContentMixin, IContentRenderer
 from pyams_utils.adapter import adapter_config, ContextAdapter
 from pyams_utils.registry import get_current_registry, get_utility, utility_config
 from pyams_utils.request import check_request
 from pyams_utils.traversing import get_parent
 from pyams_utils.vocabulary import vocabulary_config
-from zope.container.contained import Contained
-from zope.container.ordered import OrderedContainer
-from zope.lifecycleevent import ObjectCreatedEvent, IObjectAddedEvent, ObjectModifiedEvent, IObjectModifiedEvent, \
-    IObjectRemovedEvent
-from zope.location import locate
-from zope.interface import implementer
-from zope.schema.fieldproperty import FieldProperty
-from zope.schema.vocabulary import SimpleVocabulary, SimpleTerm
-
-from pyams_content import _
 
 
 #